There are numerous microphones on the market that screw on a capsule to a field effect transistor (“FET”) assembly and which send a signal to the microphone amplification stage. The mic signal is then sent to a mix board. But this type of signal is susceptible to radio frequency (“RF”) noise such as is produced by a cellular phone, TV, microwave oven or other common devices, as well as other types of noise due to the wires from the FET assembly being exposed (i.e., not shielded) until they reach the amplification stage.
There are microphones available on the market today that are RF shielded; such as pencil microphones or podium microphones in which the capsule is connected directly to the microphone metal tube housing or gooseneck, then to electronics in the microphone or at the base of gooseneck mic. The housing all the way down to the electronics is metal and therefore there are no exposed wires and the microphone housing or grill shields against RF. However, there are no known available multi-element microphones that have the electronics and capsule shielded from RF. Part of the reason is that it can be difficult to attach and capture all of the microphones and the required electronics in one contiguous housing.
The microphone of the present invention is defined by a tri-element design that has the electronics and capsule RF shielded in one housing so that there are no exposed wires and so that the devices are shielded against RF noise getting into the audio signal.
Further, wired microphones require a cable that electrically connects the microphone to the electronics or the mixer that power and control the microphone. Often, the cabling that connects the mic to the electronics creates difficulties in both positioning the mic in desired locations, and in routing the cable. For instance, if the mic is suspended by the cable and the user wants it in a particular orientation other than vertical, the cable tends to spin, making precise directional control difficult. The cable routing is also a problem in many installations. Thus, in many localities building codes, fire codes and similar ordinances place specific requirements for creating a plenum between the living or working space and the space above a drop ceiling. When the microphone cable is extended through the drop ceiling, the cable that does not create a tight seal and may compromise the plenum rating of the installation by creating a passageway from the occupied space to the space above the drop ceiling. In order to maintain the plenum rating, the opening through the ceiling where the cable extends through the ceiling is often sealed to prevent passing of air through the opening and the cable, if exposed in the plenum space, must be plenum rated or which is LSOH (“low smoke zero halogen”) material. Alternately, the cable may be run under the ceiling rather than passing it through the ceiling. This tends to be unsightly.
With existing wired microphones that have the cable extending through the ceiling with a sealed opening, the length of the cable cannot be readily adjusted below the ceiling. Therefore, changing the length of the cable to reposition the mic (both in terms of dimension and directional position) requires of the mic requires that the cable is cut, extra cable added to adjust the length, and the electronics reconnected. If the cable is shortened, the coiled up cable can get in the way and is unsightly.
There is a need therefore for apparatus that facilitates adjustment of wired microphones without destroying plenum ratings. The specific type of wiring or cabling will depend upon the types of equipment that are being wired. A very common type of cabling connection that is used in a variety of settings are the “registered jack”—“RJ”—types of connectors. These connectors are standardized physical network interfaces for connecting telecommunications or data equipment. There are many different standard designs for RJ connectors such as RJ11, RJ14, RJ21, RJ35, RJ45, Rj48 and numerous others. For purposes here, RJ connectors include a male plug attached to one end of a cable that leads to, for example, an electronic device of some kind, and a female plug attached to one end of the cable to which the electronic device is to be connected and which leads to, for example, a service provided by a local exchange carrier. The female connector typically terminates at a wall or ceiling plate that is supported by some kind of a junction box in the wall or ceiling and the cable extends from the female connector.
The standard RJ setup just described does not contemplate any seal between the male and female ends of the connectors and as such, cannot provide a plenum seal between the spaces separated by the wall or ceiling barrier. As such, where there is a desire or need to maintain a plenum seal across the barrier the RJ type of connectors present a plenum-seal-destroying problem. There is a need, therefore, for apparatus that allows a plenum seal where barrier-penetrating connectors such as RJ connectors are used.